I have recently been setting up my MacBook (running Leopard) to send email using the local email delivery system, i.e. Postfix. This means modifying the default installation to relay email through my ISP/email service – in my case; FastMail. I use FastMail because they have a nice secure email setup with both IMAP and SMTP access encrypted using SSL, but the instructions below will also work with Google Mail. The advantage of having your Apple Mac set up like this is that it enables command line scripts and various unix programs to send email. In my case, it allows me to use Mutt and Emacs as my email client.